Fluidized Bed Hot-Melt Granulation as a Tool to Improve Curcuminoid Solubility.

Curcumin is the main bioactive component of Curcuma longa L. and has recently aroused growing interest from the scientific community. Unfortunately, the medicinal properties attributed to curcuminoids are impaired by their low oral bioavailability or low solubility in aqueous solutions. Many strategies have been studied to improve curcumin solubility; however, the preparation of granules using hydrophilic materials has never been attempted. The aim of this work was to develop curcumin granules by fluidized bed hot-melt granulation using the hydrophilic carrier Gelucire® 50:13. A two-level factorial design was used to verify the influence of Gelucire® 50:13 and lactose contents found in the granules on their size, morphology, bulk and tapped densities, flow, moisture content, and water activity. The granules obtained were also evaluated by differential scanning calorimetry, thermogravimetric analysis, X-ray powder diffraction, and infrared spectrometry. The curcumin solubility and dissolution rates in water were determined by liquid chromatography. The best formulation provides an increase of curcumin solubility of 4642-fold and 3.8-fold compared to the physical mixture. The dissolution tests showed a maximum drug release from granules after 45 min of 70% at pH 1.2 and 80% at pH 5.8 and 7.4, while for non-granulated curcumin, the release was below 20% in all pH. The solid-state characterization and solubility measurement showed good stability of granules over 9 months. The results attest that the fluidized bed hot-melt granulation with hydrophilic binders is an attractive and promising alternative to obtain solid forms of curcumin with enhanced bioavailability.

Optimization of the extraction of curcumin from Curcuma longa rhizomes

The aim of this work was to study the effect of dynamic maceration factors upon the curcumin content of Curcuma longa L., Zingiberaceae, extracts and to determine the optimum set of parameters for the extraction of curcumin using a 2(5) full factorial design and the response surface methodology. Under the established conditions, the content of soluble solids and curcumin in the extracts ranged from 0.8 to 3.4%, and from 0.1 to 1.8%, respectively. The most influential variable observed for the extraction was the ethanolic strength of the solvent. The optimized condition involves an extraction time of 12 h, agitation speed of 30 rpm, drug to solvent ratio of 1/6, extraction temperature of 80 ºC and the solvent with ethanolic strength of 70%. The data reported herein are useful for further developments of curcuma phytopharmaceutical intermediate products with optimized characteristics.